The present invention relates to a process for determining the camber or curved deformation of a metal sheet and a device for carrying out said process.
Economical requirements increasingly oblige steel manufacturers to automate their production lines to improve the profitability of their plants.
However, some operations, such as in particular the manufacture of sheets, cannot be completely automated since the shapes of the mother sheets issuing from the rolling mill or planifying machine, differ from one sheet to the other. It is therefore very difficult to automate the rest of the production line since no precise information is available concerning the shape of the sheets.
Furthermore, it is also desirable to know certain characteristics of the sheets resulting from the shape of the latter so as to permit, for example, an adjustment of the rolling mill for eliminating possible defects.
Indeed, the steelworks supplies to the sheet metal shop a semi-product termed bloom. One of the functions of the sheet metal shop is to put the final product in the final dimension according to the specifications of the client.
This operation has several stages:
on the rolling line: the transformation of the bloom into a mother sheet by a hot rolling;
on the shearing line: the cutting out from the mother sheet of one or more daughter sheets. This operation is itself subdivided into two successive parts:
1--the cutting of the edges of the mother sheet so as to provide the width required by the client. This operation is carried out with an edge shearing tool, and
2--the cutting of the mother sheet which has already had its edges cut to size of daughter sheets to the length required by the client. This operation is carried out with a dividing shearing tool.
The shearing operation is carried out according to this procedure provided the mother sheet is sufficiently rectangular to permit inscribing the daughter sheets therein. If the mother sheet is bent, it is necessary to effect a cutting of the mother sheet into sections before cutting its edges. This anomaly disturbs the flow of products in the shearing line, results in increased manufacturing costs and sometimes involves the rejection of the metal.
Now, at the present time, there is no means for industrially measuring the bend in the mother sheet in the plane of the latter, which bend or rise is also termed a camber.
Thus a bent mother sheet reaches the edge shearing station without the operator being previously informed thereof, which all the more disturbs the flow of products.
Furthermore, the camber defect is generally created in the rolling mill when the latter is badly adjusted. Now,
rolling mill operator only has a qualitative idea of
the camber based on his visual appreciation and that of the planar-rendering machine operator. It is therefore very difficult,
at the present time, to determine the ideal adjustment of the rolling mill.
This is all the more true as the bent defect is all the easier to see as the mother sheet is long. It is quite possible not to realize a defect in the adjustment of the rolling mill in a series of short mother sheets and to produce an unacceptable defect in the first long sheet.
An object of the invention is therefore to solve these problems by proposing a process and device which permit characterizing the bent defect by quantitative values which are simple, reliable and relatively inexpensive.